The .45ACP cartridge was designed around a military powder than came later to be known as Bullseye.
The fastest powders work the best in this old warhorse, and of course, nothing beats Bullseye for accuracy.
Winchester's replacement for Bullseye is WST, Winchester Super Target. It flows well and burns much cleaner than Bullseye. Another benefit is that it is advertised as "low report"- it's quieter. And it is; I get calls for the chrono when I shoot WST in IDPA and USPSA, and I know I'm making the floor.
Yet another plus for using WST or its other equivalents like Bullseye and Vihta Vuori 310 is that in self-loaders like the 1911, the felt recoil will be less, especially if you use heavier bullets.
A couple of years ago I set up a blind test at the club with a group of different loads all using 230gr Rainier plated round-noses. They were loaded into magazines in alternating pairs by the guy who wasn't shooting.
All of them chronoed within a 30fps range excepting the last, VV340.
I had a non-1911 guy, a Glocker, run my Government Model with these mixed magazines, going through an easy hundred-plus rounds.
The order of felt recoil from least to most, according to Bob and, not coincidentally, me, too:
WST, Bullseye, VV310, tie
VV320
Unique
231
VV340, slower and particularly bad.
Try it yourself and see.
WST is the quietest, too, a winner for me. I don't need the distraction.
It's cheap, available, and pretty clean. It's only downside is a certain amount of temperature variation.
The last 20,000+ rounds of .45ACP I've loaded have been with WST.